Activist Erin Brockovich was arrested for driving a powerboat while drunk, officials said yesterday.

Brockovich — famously played by Julia Roberts in the 2000 hit film “Erin Brockovich” — was busted on Lake Mead, near Las Vegas, as she tried to maneuver her boat into a marina slip Friday night, officials said.

She allegedly blew a .16 blood-alcohol level, twice the legal limit to operate a boat or car in Nevada.

“The game warden saw she was struggling to pull her boat into dock and went to help,” said Edwin Lyngar, a spokesman for the state Department of Wildlife. “In he process, it became apparent that [Brockovich] was under the influence.”

She was charged with operating a boat under the influence, a misdemeanor that could cost her $1,600.,